Medical Dictionary

Widal reaction

noun Wi·dal reaction
variants: also

Widal's reaction


Medical Definition of Widal reaction

  1. :  a specific reaction consisting in agglutination of typhoid bacilli or other salmonellae when mixed with serum from a patient having typhoid fever or other salmonella infection and constituting a test for the disease

Biographical Note for widal reaction




(1862–1929), French physician and bacteriologist. Widal held a professorship of pathology and internal medicine at the University of Paris. In 1896 he developed the Widal reaction, a procedure for diagnosing typhoid fever based on the fact that antibodies in the blood of an infected individual cause the bacteria to bind together into clumps. In 1906 he recognized that the retention of sodium chloride was a feature found in cases of nephritis and cardiac edema, and he recommended salt deprivation as part of the treatment for both diseases.

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contemplative of or relative to the past

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